Seismic Frequency Loss Mechanisms: Direct Observation

Batzle, Michael; Kumar, Gautam; Hofmann, Ronny; Duranti, Luca; Adam, Ludmila

doi:10.3997/2214-4609.201405180

Cited by 4 publications

(7 citation statements)

References 7 publications

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“…Nevertheless, we observe Q to be constant or increasing with frequency, as we do for the seismic wave speeds. This is in concordance with viscoelastic models, in general, and the work on mudstones by Batzle et al [], in particular.…”

Section: Discussionsupporting

confidence: 91%

Resonant ultrasound spectroscopy of horizontal transversely isotropic samples

Watson

Wijk

2015

JGR Solid Earth

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Most crustal rocks present some amount of directional dependence of seismic speeds, particularly mudstones (also termed "shales"). Hence, accurate imaging of the subsurface requires anisotropic models and integration of rock physics information in order to constrain the inherent nonuniqueness of the inversion from seismic data. Resonant ultrasound spectroscopy provides estimates of the full anisotropic stiffness tensor from resonant frequencies of geological core samples, along with a measure of intrinsic attenuation. We have developed new functionality to existing codes which enable horizontal transversely isotropic samples to be analyzed. We compared and discussed estimations of the elastic properties of mudstone samples with hexagonal symmetry; one sample was drilled parallel and one perpendicular to the layering. While spatial heterogeneity in the mudstone prevented a direct correlation of the elastic parameters of each sample, time-of-flight measurements reveal frequency dispersion of the elastic parameters that is consistent between the samples.

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Section: Discussionsupporting

confidence: 91%

Resonant ultrasound spectroscopy of horizontal transversely isotropic samples

Watson

Wijk

2015

JGR Solid Earth

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“…Moreover, note that this is the velocity dispersion caused by pure fluids. The heavy oil‐filled sands have even smaller dispersion than the heavy oil itself (Batzle et al, ). In practice, heavy oils in the glassy solid status are considered as elastic, and the velocity dispersion mainly occurs at the quasi‐liquid status (Han et al, 2008). By comparing the spectral seismic signatures of baseline and monitor line as shown in Figure , it can be found that the high‐frequency component of the strong seismic reflection events of carbonate layers beneath the steam chamber on the monitor line is gone.…”

Section: Discussionmentioning

confidence: 99%

“…From a more general perspective, in spite of the very low permeability characteristics, shales are heterogeneous porous rocks, more or less containing elastic heterogeneities. Frequency‐dependent elastic behaviors of shales based on the laboratory measurements have been reported by Jones and Wang (), Duranti et al (), Hofmann (), Batzle et al (), and Bauer et al (). Therefore, shales should also be considered as naturally dispersive geomaterials, even their characteristic frequency might occur at very low frequency range since it takes extremely long time to achieve pore pressure equilibration (Batzle et al, ).…”

Section: Mobility Effect On Poroelastic Seismic Reflectivitymentioning

confidence: 99%

“…By using visual inspection of partially saturated limestones, Cadoret et al () presented the dependence of measured compressional velocity upon frequency and fluid distribution. Batzle et al (, ) presented the frequency‐dependent velocity characteristic in a partially saturated rock using a forced deformation system. Tisato and Quintal () reported measurements of frequency‐dependent dispersion and attenuation in partially saturated Berea sandstone to shed light on the evidence of fluid flow on the mesoscopic scale.…”

Section: Introductionmentioning

confidence: 99%

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Mobility Effect on Poroelastic Seismic Signatures in Partially Saturated Rocks With Applications in Time‐Lapse Monitoring of a Heavy Oil Reservoir

et al. 2017

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Conventional seismic analysis in partially saturated rocks normally lays emphasis on estimating pore fluid content and saturation, typically ignoring the effect of mobility, which decides the ability of fluids moving in the porous rocks. Deformation resulting from a seismic wave in heterogeneous partially saturated media can cause pore fluid pressure relaxation at mesoscopic scale, thereby making the fluid mobility inherently associated with poroelastic reflectivity. For two typical gas‐brine reservoir models, with the given rock and fluid properties, the numerical analysis suggests that variations of patchy fluid saturation, fluid compressibility contrast, and acoustic stiffness of rock frame collectively affect the seismic reflection dependence on mobility. In particular, the realistic compressibility contrast of fluid patches in shallow and deep reservoir environments plays an important role in determining the reflection sensitivity to mobility. We also use a time‐lapse seismic data set from a Steam‐Assisted Gravity Drainage producing heavy oil reservoir to demonstrate that mobility change coupled with patchy saturation possibly leads to seismic spectral energy shifting from the baseline to monitor line. Our workflow starts from performing seismic spectral analysis on the targeted reflectivity interface. Then, on the basis of mesoscopic fluid pressure diffusion between patches of steam and heavy oil, poroelastic reflectivity modeling is conducted to understand the shift of the central frequency toward low frequencies after the steam injection. The presented results open the possibility of monitoring mobility change of a partially saturated geological formation from dissipation‐related seismic attributes.

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“…Several experiments have been conducted to characterize the dispersion and attenuation of waves caused by the WIFF [5,8,33,[43][44][45][46][47]. In the low-and high-frequency regimes, the velocity and the elastic moduli are nearly constants.…”

Section: Heterogeneities At Mesoscopic and Microscopic Scalesmentioning

confidence: 99%